Exchange 2003 installation requires different permissions for different tasks - If you are installing the first Exchange 2003 in a forest, then you must run forestprep, which requires Enterprise admin and Schema admin permissions - If you are installling the first Exchange 2000 in a domain, then you must run domainprep, which requires Domianadmin permission. Of course, local machine admine permission is also required For users, they do not need specific permission, as long as they are allowed to access Exchange mailboxes
